By the orthodox pali canon are animals, hell beings, etc. able to practice dhamma and achieve enlightenment?

I remember sutta references to the buddha teaching man and gods so it would seem there is references to the above human realm learning and having achievements. Though I should be noted on this as I am going by memory and not sutta reference which is important.

Although I appreciate the directness can you provide sutta references?

**On a side note I was thinking about the Lord Buddha providing discourses to the higher realms. If higher form realms/immaterial realms can receive dhamma discourse and path achievements than why not the lower? ((Though I too need to locate references to establish this potential memory))

That is why sutta references are a must. Or we will end up with discussions based on opinion and other related frameworks such as the Mahayana "Buddha-Nature" framework.

---The trouble is that you think you have time------Worry is the Interest, paid in advance, on a debt you may never owe------It's not what happens to you in life that is important ~ it's what you do with it ---

So between the racking pain and tortures, don't think beings born in hell can set aside time for dhamma learning.

Beings that are born as petas or hungry ghost are just constantly hungry. You need just look at yourself as a human to know that when you are hungry, you pretty much can't do anything until you have eaten. So imagine feeling that 24/7, how can anyone learn anything in that state.

Beings that are born as animals have very basic instincts which needs to be fulfilled. So its eat, propogate, rest, sleep and eat. Besides, how do you teach them dhamma when they do not have the faculties to understand complex language beyond the redumentary communication tools they are bestowed with?

Beings born in the asura realm are constantly angry and warring with each other and devas. I think they may have some chance to learn the dhamma but maybe due to their state of mind, being angry all the time, they do not have the requisite to learn it.

Most beings born in the celestial realms are previleaged, enjoy sensory pleasures that are highten to such an extent they don't experience suffering or are in a constantly blissful state, so they are unlikely to think about learning the dhamma.

Wheras we humans are most fortunate to be exposed to both suffering and happiness. Beacause we get to see and experience both sides of the coin and have the right faculty of learning, we have the highest chance to be awaken.

I think though when those natural existences and inner existential landscapes are really thought on it doesn't really hold up as disqualifying factor. Or maybe it does (Sutta probably will turn this question on it's head like it does other's by showing its based on the wrong premises and why those premises are mistaken).

Lastly the "unconditioned", etc is exactly that. I'm not sure those standpoints hold up for disqualifying path achievements.

I posted in Classical Theravada because particularly i'm looking for classical sutta standpoints.

I know the original poster asked for sutta references, but perhaps it's of interest to look at what the abhidhamma has to say about it. According to it, awakening requires what it terms a triple-rooted rebirth consciousness, which beings in woeful states don't have. See chapter 4 sections 24 and 25 of A Comprehensive Manual of Abhidhamma, edited by Bhikkhu Bodhi.